U.S. patent number 10,175,815 [Application Number 15/388,872] was granted by the patent office on 2019-01-08 for electrostatic input device.
This patent grant is currently assigned to Alps Electric Co., Ltd.. The grantee listed for this patent is Alps Electric Co., Ltd.. Invention is credited to Naoyuki Hatano, Kazuhito Oshita.
United States Patent |
10,175,815 |
Oshita , et al. |
January 8, 2019 |
Electrostatic input device
Abstract
There is provided an electrostatic input device including a
plurality of electrodes, and receiving an input operation according
to electrostatic capacitances generated between the plurality of
electrodes and an object when the object comes close to a detection
surface, the device including a variation detection unit configured
to detect variations in the electrostatic capacitances, a
determination unit configured to determine whether the object
coming close to the detection surface is the fingertip or the palm
on the basis of the variations detected by the variation detection
unit, and a control unit configured to inhibit reception of an
input operation on the detection surface for a predetermined period
of time in a case where the determination unit determines that the
object coming close to the detection surface is the palm.
Inventors: |
Oshita; Kazuhito (Miyagi-ken,
JP), Hatano; Naoyuki (Miyagi-ken, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Alps Electric Co., Ltd. |
Ota-ku, Tokyo |
N/A |
JP |
|
|
Assignee: |
Alps Electric Co., Ltd. (Tokyo,
JP)
|
Family
ID: |
59496376 |
Appl.
No.: |
15/388,872 |
Filed: |
December 22, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170228083 A1 |
Aug 10, 2017 |
|
Foreign Application Priority Data
|
|
|
|
|
Feb 4, 2016 [JP] |
|
|
2016-019485 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F
3/0446 (20190501); G06F 3/0416 (20130101); G06F
3/044 (20130101); G06F 2203/04108 (20130101) |
Current International
Class: |
G06F
3/041 (20060101); G06F 3/044 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Shen; Yuzhen
Attorney, Agent or Firm: Beyer Law Group LLP
Claims
What is claimed is:
1. An electrostatic input device comprising: a detection surface
configured to receive an input operation of an object approaching
thereto, the detection surface including at least one specific
region set at an end of the detection surface; a plurality of
electrodes, electrostatic capacitances being generated between the
plurality of electrodes and the object when the object comes close
to the detection surface; and a microcomputer connected to the
plurality of electrodes, the microcomputer: detecting variations in
the electrostatic capacitances for the plurality of electrodes;
determining whether or not there is a touch on the detection
surface by the object; determining whether or not the touch is the
input operation on the at least one specific region of the
detection surface, if it is determined that there is the touch on
the detection surface; permitting reception of the input operation
by the detection surface if it is determined that the touch is not
the input operation on the at least one specific region;
determining whether the object coming close to the detection
surface is a fingertip or a palm on the basis of the detected
variations if it is determined that there is no touch on the
detection surface; and inhibiting the reception of the input
operation by the detection surface for a predetermined period of
time if it is determined that there is no touch and the object
coming close to the detection surface is the palm, wherein the
determining that the object coming close to the detection surface
is the palm includes: calculating an integrated value of the
variations in the electrostatic capacitances formed between the
object and the plurality of electrodes for each of the at least one
specific region while there is no touch on the detection surface;
obtaining a moving average of the integrated value of the
variations in the electrostatic capacitances for each of the at
least one specific region; and determining that the object is the
palm if the moving average of the integrated value exceeds a
threshold value.
2. The electrostatic input device according to claim 1, wherein the
microcomputer inhibits the reception of the input operation by
inhibiting an inhibition region of the detection surface from
receiving the input operation for the predetermined period of time
if it is determined that the object coming close to the detection
surface is the palm.
3. The electrostatic input device according to claim 2, wherein the
microcomputer stops inhibiting the reception of the input operation
if another input operation is performed on the detection surface
other than the inhibition region thereof.
4. The electrostatic input device according to claim 1, wherein the
microcomputer sets a plurality of specific regions on the detection
surface and determines, for each of the plurality of specific
regions, if the object coming close to the detection surface is the
palm, and inhibits the reception of the input operation by
inhibiting a corresponding inhibition region of the detection
surface from receiving the input operation for the predetermined
period of time if it is determined, for one of the plurality of
specific regions, that the object coming close to the detection
surface is the palm.
5. An electrostatic input device comprising: a detection surface
configured to receive an input operation of an object approaching
thereto, the detection surface including at least one specific
region set at an end of the detection surface; and a plurality of
electrodes, electrostatic capacitances being generated between the
plurality of electrodes and the object when the object comes close
to the detection surface, wherein the electrostatic input device is
installed with a program causing the electrostatic input device to
execute the steps of: detecting variations in the electrostatic
capacitances for the plurality of electrodes; determining whether
or not there is a touch on the detection surface; determining
whether or not the touch is the input operation on the at least one
specific region of the detection surface if it is determined that
there is the touch on the detection surface; permitting reception
of the input operation by the detection surface if it is determined
that the touch is not the input operation on the at least one
specific region; determining whether the object coming close to the
detection surface is a fingertip or a palm on the basis of the
detected variations if it is determined that there is no touch on
the detection surface; and inhibiting the reception of the input
operation by the detection surface for a predetermined period of
time if it is determined that there is no touch and the object
coming close to the detection surface is the palm, wherein the
determining that the object coming close to the detection surface
is the palm includes: calculating an integrated value of the
variations in the electrostatic capacitances formed between the
object and the plurality of electrodes for each of the at least one
specific region while there is no touch on the detection surface;
obtaining a moving average of the integrated value of the
variations in the electrostatic capacitances for each of the at
least one specific region; and determining that the object is the
palm if the moving average of the integrated value exceeds a
threshold value.
Description
CLAIM OF PRIORITY
This application claims benefit of Japanese Patent Application No.
2016-019485 filed on Feb. 4, 2016 which is hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a touch pad mounted on a notebook
PC or the like.
2. Description of the Related Art
A touch pad is generally mounted on a notebook PC as a kind of
pointing device. A user can operate a mouse pointer by tracing the
touch pad with the finger. In recent years, a size of such a touch
pad has been increased, and thus the palm easily comes into contact
with the touch pad when a keyboard is operated. Thus, an operation
error easily occurs.
Therefore, the following touch pad has been proposed. That is, in a
case where a contact position is a peripheral portion on which the
palm is frequently placed, it is determined that a contact region
is formed by the palm if spatial characteristics (an area and an
aspect ratio) corresponding to an area and a length of the contact
region exceed a first condition corresponding to a predetermined
area and length, and it is determined that the contact region is
formed by the fingertip if the spatial characteristics do not
exceed the first condition. In a case where a contact position is a
central portion on which the fingertip is frequently placed, it is
determined that a contact region is formed by the palm if the
spatial characteristics exceed a second condition corresponding to
an area and a length larger than the first condition, and it is
determined that the contact region is formed by the fingertip if
the spatial characteristics do not exceed the second condition.
Japanese Unexamined Patent Application Publication No. 2015-32177
is an example of the related art.
As mentioned above, in the related art, there is a need for a touch
pad which can effectively prevent an operation error caused by the
palm and allows a normal operation using the fingertip to be
smoothly performed.
SUMMARY OF THE INVENTION
The present invention provides an electrostatic input device and a
program for the electrostatic input device, capable of effectively
preventing an operation error caused by the palm and allowing a
normal operation using the fingertip to be smoothly performed.
According to an aspect of the present invention, there is provided
an electrostatic input device including a plurality of electrodes,
and receiving an input operation according to electrostatic
capacitances generated between the plurality of electrodes and an
object when the object comes close to a detection surface, the
device including a variation detection unit configured to detect
variations in the electrostatic capacitances; a determination unit
configured to determine whether the object coming close to the
detection surface is the fingertip or the palm on the basis of the
variations detected by the variation detection unit; and a control
unit configured to inhibit reception of an input operation on the
detection surface for a predetermined period of time in a case
where the determination unit determines that the object coming
close to the detection surface is the palm.
According to the configuration, the electrostatic input device
includes the variation detection unit that detects variations in
the electrostatic capacitances, the determination unit that
determines whether the object coming close to the detection surface
is the fingertip or the palm on the basis of the variations
detected by the variation detection unit, and the control unit that
inhibits reception of an input operation on the detection surface
for a predetermined period of time in a case where the
determination unit determines that the object coming close to the
detection surface is the palm. Therefore, since an input operation
using the palm is inhibited in a case where it is determined that
an object coming close to the detection surface is the palm, it is
possible to effectively prevent an operation error caused by the
palm, and also to smoothly perform a normal operation using the
fingertip. In a case where a determination is performed on the
basis of only a contact state (an area, a length, or the like of a
contact region), if the palm comes into slight contact with the
detection surface, the palm cannot be discriminated from the
finger. In a case where a determination is performed on the basis
of a proximity state, discrimination accuracy between a large
object and a small object is improved (in a case where a
determination is also performed on the basis of integration,
discrimination accuracy is further improved).
According to the aspect of the present invention, preferably, the
determination unit determines that the object coming close to the
detection surface is the palm if an integrated value of variations
corresponding to a plurality of electrodes in a specific region of
the detection surface, detected by the variation detection unit,
exceeds a first threshold value.
In a case where the palm does not come into contact with the
detection surface, detection is difficult since variations in
electrostatic capacitances corresponding to the electrodes are very
small. However, according to the configuration, there is the use of
an integrated value of variations corresponding to a plurality of
electrodes in the specific regions of the detection surface,
detected by the variation detection unit. Therefore, even in a case
where the palm does not come into contact with the detection
surface, and thus variations in electrostatic capacitances
corresponding to the electrodes are very small, it is possible to
determine that the palm comes close to the detection surface. Thus,
it is possible to effectively prevent an operation error caused by
the palm, and also to smoothly perform a normal operation using the
fingertip. Since the palm is larger than the finger, it is possible
to determine that the palm comes close to the detection surface by
using an integrated value in the region even if a variation in an
each electrostatic capacitance is small.
According to the aspect of the present invention, preferably, the
determination unit determines that the object coming close to the
detection surface is the palm if a movement average value of an
integrated value of variations corresponding to a plurality of
electrodes in a specific region of the detection surface, detected
by the variation detection unit, exceeds a second threshold
value.
According to the configuration, since it is determined that an
object coming close to the detection surface is the palm by using
the movement average value of the integrated value, it is possible
to reduce the influence of noise such as a sudden increase or
decrease in an integrated value. Consequently, it is possible to
more accurately determine that the palm comes close to the
detection surface.
According to the aspect of the present invention, preferably, the
control unit inhibits reception of an input operation on an
inhibition region of the detection surface for a predetermined
period of time in a case where the determination unit determines
that the object coming close to the detection surface is the
palm.
According to the configuration, in a case where it is determined
that an object coming close to the detection surface is the palm,
it is possible to inhibit reception of an input operation on a
region with which the palm easily comes into contact. Thus, it is
possible to smoothly perform a normal operation using the
fingertip.
According to the aspect of the present invention, preferably, the
control unit cancels inhibition of an input operation on the
detection surface in a case where an input operation is performed
on regions other than the inhibition region.
According to the configuration, in a case where an input operation
is performed on regions other than the specific region, there is a
high probability that the operation may be performed with the
finger, and thus it is possible to smoothly perform a normal
operation using the fingertip by canceling the inhibition of an
input operation on the specific region.
According to the aspect of the present invention, preferably, the
control unit sets the specific region at an end of the detection
surface.
According to the configuration, since the specific region is set
the end of the detection surface with which the palm easily comes
into contact, and thus it is possible to more effectively prevent
an operation error caused by the palm.
According to the aspect of the present invention, preferably, the
control unit sets a plurality of the specific regions on the
detection surface.
According to the configuration, since a plurality of specific
regions are set on the detection surface, it is possible to
effectively prevent an operation error caused by the palm at the
upper end or the left and right ends of the detection surface with
which the palm easily comes into contact.
According to the aspect of the present invention, preferably, the
control unit performs a process of inhibiting reception of an input
operation on an inhibition region of the detection surface for a
predetermined period of time for each of the plurality of set
specific regions.
According to the configuration, since a plurality of specific
regions are set on the detection surface, it is possible to
effectively prevent an operation error caused by the palm at the
upper end or the left and right ends of the detection surface with
which the palm easily comes into contact.
According to another aspect of the present invention, there is
provided a program for an electrostatic input device which includes
a plurality of electrodes, and receives an input operation
according to electrostatic capacitances generated between the
plurality of electrodes and an object when the object comes close
to a detection surface, the program causing the electrostatic input
device to execute a step of detecting variations in the
electrostatic capacitances; a step of determining whether the
object coming close to the detection surface is the fingertip or
the palm on the basis of the detected variations; and a step of
inhibiting reception of an input operation on the detection surface
for a predetermined period of time in a case where it is determined
that the object coming close to the detection surface is the
palm.
According to configuration, the program causes the electrostatic
input device to execute a step of detecting variations in the
electrostatic capacitances; a step of determining whether the
object coming close to the detection surface is the fingertip or
the palm on the basis of the detected variations; and a step of
inhibiting reception of an input operation on the detection surface
for a predetermined period of time in a case where it is determined
by a determination unit that the object coming close to the
detection surface is the palm. Therefore, since an input operation
using the palm is inhibited in a case where it is determined that
an object coming close to the detection surface is the palm, it is
possible to effectively prevent an operation error caused by the
palm, and also to smoothly perform a normal operation using the
fingertip.
According to the electrostatic input device and the program for the
electrostatic input device of the aspects of the present invention,
it is possible to effectively prevent an operation error caused by
the palm and to smoothly perform a normal operation using the
fingertip.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a state in which an electrostatic input device
according to an embodiment of the present invention is mounted on a
notebook PC.
FIG. 2 is a system configuration diagram of the electrostatic input
device according to the embodiment of the present invention.
FIG. 3 is a plan view of the electrostatic input device according
to the embodiment of the present invention.
FIG. 4 is a flowchart for explaining an operation of the
electrostatic input device according to the embodiment of the
present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment
FIG. 1 is a diagram illustrating a state in which an electrostatic
input device 2 according to an embodiment is mounted on a notebook
PC 1. FIG. 2 is a plan view of the electrostatic input device 2
according to the embodiment. FIG. 3 is a system configuration
diagram of the electrostatic input device 2 according to the
embodiment. Hereinafter, with reference to FIGS. 1 to 3, a
description will be made of the electrostatic input device 2
according to the embodiment.
The electrostatic input device 2 is, for example, a touch pad, and
is mounted on the notebook PC 1 as illustrated in FIG. 1. An
operation plate is bonded to the uppermost surface of the
electrostatic input device 2, and a surface of the operation plate
is a detection surface 3 for detecting an operation performed by a
user.
As illustrated in FIG. 2, a plurality of specific regions 3A to 3C
are set on the detection surface 3. Here, the specific regions 3A
to 3C are set at ends of the detection surface 3 with which the
palm easily comes into contact during an input operation on a
keyboard illustrated in FIG. 1 or the detection surface 3. The
specific regions 3A to 3C are set at the ends of the detection
surface 3 with which the palm easily comes into contact, and thus
it is possible to effectively prevent an operation error due to
contact or proximity of the palm.
In the present embodiment, in FIG. 2, the specific region 3A is set
at the upper end of the detection surface 3, the specific region 3B
is set at the right end of the detection surface 3, and the
specific region 3C is set at the left end of the detection surface
3. However, setting of specific regions is not limited to the
example illustrated in FIG. 2, and only one specific region may be
set on the detection surface 3, and four or more specific regions
may be set on the detection surface 3. A specific region may be set
at locations other than the ends of the detection surface 3. The
specific regions 3A to 3C are set on the detection surface 3 by
control means 8 which will be described later, and are not separate
physically.
As illustrated in FIG. 3, the electrostatic input device 2 includes
a group of a plurality of X electrodes 5 and a group of a plurality
of Y electrodes 6 provided on a substrate 4, and the electrodes are
connected to the control means 8 via wirings 7. The control means 8
applies a voltage to one of the X electrode group 5 or the Y
electrode group 6 as driving electrodes, detects the voltage with
the other group as detection electrodes, and detects a variation in
an electrostatic capacitance obtained when the finger or the palm
comes close to the substrate 4, so as to detect the proximity of
the palm. The X electrodes 5 and the Y electrodes 6 of the present
embodiment are detection means for outputting a voltage converted
into an electrostatic capacitance value, but are not limited
thereto, and may be, for example, of a type of detecting and
outputting other variations in an operation pressure or the like
during an operation of a touch pad.
As illustrated in FIG. 3, the control means 8 includes a variation
detection unit 81, an integrated value calculation unit 82, a
movement average value calculation unit 83, a determination unit
84, a control unit 85, and a counter 86. The variation detection
unit 81 detects variations in electrostatic capacitances of the X
electrodes 5 and the Y electrodes 6. The integrated value
calculation unit 82 calculates an integrated value of variations
corresponding to the plurality of electrodes in the specific
regions 3A to 3C of the detection surface 3, detected by the
variation detection unit 81, for each of the specific regions 3A to
3C.
The control means 8 is, for example, a microcomputer, and realizes
functions of at least some of the variation detection unit 81, the
integrated value calculation unit 82, the movement average value
calculation unit 83, the determination unit 84, the control unit
85, and the counter 86 illustrated in FIG. 3 by executing a program
101 for the electrostatic input device.
The movement average value calculation unit 83 calculates a
movement average value (which is a movement average value in a time
axis) of the integrated value calculated for each of the specific
regions 3A to 3C by the integrated value calculation unit 82, for
each of the specific regions 3A to 3C. The movement average value
calculation unit 83 of the present embodiment calculates the
movement average value of the integrated value calculated for each
of the specific regions 3A to 3C by using a simple movement
average, but may calculate the movement average value of the
integrated value calculated for each of the specific regions 3A to
3C by using a weighted movement average or an index movement
average.
The determination unit 84 determines whether or not there is a
touch operation on the detection surface 3. The determination unit
84 determines whether an object approaching the detection surface 3
is the fingertip or the palm on the basis of variations detected by
the variation detection unit 81. Specifically, the determination
unit 84 compares the movement average values calculated for the
respective specific regions 3A to 3C by the movement average value
calculation unit 83 with threshold values A to C (second threshold
values) set in the specific regions 3A to 3C.
The determination unit 84 determines that the approaching object is
the palm in a case where the respective movement average values for
the specific regions 3A to 3C exceed the corresponding threshold
values A to C as comparison results, and determines that the
approaching object is the fingertip, and determines that the
approaching object in a case where the respective movement average
values do not exceed the corresponding threshold values A to C.
For example, in a case where the movement average value for the
specific region 3A exceeds the corresponding threshold value A as a
comparison result, the determination unit 84 determines that the
palms comes close to the specific region 3A. Similarly, in a case
where the movement average value for the specific region 3B exceeds
the corresponding threshold value B, the determination unit 84
determines that the palms comes close to the specific region 3B.
Further, in a case where the movement average value for the
specific region 3C exceeds the corresponding threshold value C, the
determination unit 84 determines that the palms comes close to the
specific region 3C.
The control unit 85 sets the specific regions 3A to 3C described in
FIG. 2 at the ends of the detection surface 3. In a case where the
determination unit 84 determines that an object coming close to the
detection surface 3 is the palm, the control unit 85 inhibits
reception of an input operation on the detection surface 3.
Specifically, in a case where the determination unit 84 determines
that an object approaching the detection surface 3 is the palm, the
control unit 85 inhibits reception of an input operation on a
region in which the approaching object is the palm for a
predetermined period of time. Here, the control unit 85 separately
performs the inhibition of reception of an input operation on a
specific region for a predetermined period of time for each of the
specific regions 3A to 3C.
In other words, in a case where the determination unit 84
determines that the palm comes close to the specific region 3A, the
control unit 85 inhibits reception of an input operation on the
specific region 3A for a predetermined period of time. In a case
where the determination unit 84 determines that the palm comes
close to the specific region 3B, the control unit 85 inhibits
reception of an input operation on the specific region 3B for a
predetermined period of time. Further, in a case where the
determination unit 84 determines that the palm comes close to the
specific region 3C, the control unit 85 inhibits reception of an
input operation on the specific region 3C for a predetermined
period of time.
Regions (inhibition regions) on which an input operation is
inhibited are not limited to the specific regions 3A to 3C, and
specific regions (detection region) may not necessarily be the same
as inhibition regions (regions on which an input operation is
inhibited). For example, an area of detection regions (specific
regions) is larger than that of inhibition regions, and partial
sizes thereof may be different from each other. Such regions are
adjusted as appropriate depending on the proximity detection
sensitivity or the like.
In a case where an input operation on regions other than a specific
region to which the palm is determined as coming close in the
detection surface 3 is performed when reception of an input
operation is inhibited, the control unit 85 cancels the inhibition
of an input operation on the specific region to which the palm is
determined as coming close. The control unit 85 controls an
operation of the counter 86.
The counter 86 measures time in response to an instruction from the
control unit 85. Different values may be set for the respective
specific regions as input operation reception inhibition time.
FIG. 4 is a flowchart for explaining an operation of the
electrostatic input device 2 according to the embodiment.
Hereinafter, with reference to FIGS. 1 to 4, a description will be
made of the operation of the electrostatic input device 2 according
to the embodiment. In the operation illustrated in the flowchart of
FIG. 4, if a cycle from starting to ending is completed, the next
cycle is executed from starting.
First, the variation detection unit 81 detects variations in
electrostatic capacitances corresponding to the X electrodes 5 and
the Y electrodes 6 (step S101). Next, the determination unit 84
determines whether or not there is a touch on the detection surface
3 (step S102), and determines whether or not the touch is an input
operation on the specific regions 3A to 3C (step S103) if there is
the touch (Yes in step S102). If the touch is an input operation on
the specific regions 3A to 3C (Yes in step S103), the determination
unit 84 determines whether or not there is a residual count value
in the counter measuring the input operation reception inhibition
time (step S104).
In a case where there is the residual count value (Yes in step
S104), the control unit 85 inhibits reception of an input operation
(step S105). In a case where the touch is not an input operation on
the specific regions 3A to 3C (No in step S103), the control unit
85 clears the counter (sets the counter to 0) (step S106). Next,
the control unit 85 clears movement average values (sets the
movement average values to 0) (step S107), and permits reception of
an input operation (step S108). In a case where there is no
residual count value (No in step S104), the control unit 85 clears
movement average values (sets the movement average values to 0)
(step S107), and permits reception of an input operation (step
S108).
In a case where there is no touch (No in step S102), the integrated
value calculation unit 82 calculates integrated values of
variations corresponding to a plurality of electrodes in the
specific regions 3A to 3C of the detection surface 3, detected by
the variation detection unit 81, for the respective specific
regions 3A to 3C (step S109). Next, the movement average value
calculation unit 83 calculates movement average values of the
integrated values calculated for the respective specific regions 3A
to 3C by the integrated value calculation unit 82, for the
respective specific regions 3A to 3C (step S110).
Next, the determination unit 84 determines whether an object coming
close to the detection surface 3 is the fingertip or the palm on
the basis of the variations detected by the variation detection
unit 81. Specifically, the determination unit 84 compares the
movement average values calculated for the respective specific
regions 3A to 3C by the movement average value calculation unit 83
with threshold values A to C (second threshold values) set in the
specific regions 3A to 3C (step S111).
In a case where the respective movement average values for the
specific regions 3A to 3C exceed the corresponding threshold values
A to C (Yes in step S111), the determination unit 84 determines
that the palm comes close, and the control unit 85 sets the counter
to, for example, 500 msec (step S112). The value of the counter
corresponds to the input operation reception inhibition time. In a
case where the respective movement average values do not exceed the
corresponding threshold values A to C (No in step S111), the
control unit 85 reduces a value of the counter to 0 (for example, 8
msec) in accordance with the elapsed time (step S113).
As mentioned above, the electrostatic input device 2 according to
the present embodiment includes a plurality of electrodes 5 and 6,
receives an input operation according to electrostatic capacitances
generated between the plurality of electrodes 5 and 6 and an object
when the object comes close to the detection surface 3, and
includes the variation detection unit 81 that detects variations in
the electrostatic capacitances, the determination unit 84 that
determines whether the object coming close to the detection surface
3 is the fingertip or the palm on the basis of the variations
detected by the variation detection unit 81, and the control unit
85 that inhibits reception of an input operation on the detection
surface 3 for a predetermined period of time in a case where the
determination unit 84 determines that the object coming close to
the detection surface 3 is the palm. Since an input operation is
inhibited in a case where an object coming close to the detection
surface is the palm, it is possible to effectively prevent an
operation error caused by the palm, and also to smoothly perform a
normal operation using the fingertip. In a case where a
determination is performed on the basis of a contact state (an
area, a length, or the like), if the palm comes into slight contact
with the detection surface, the palm cannot be discriminated from
the finger. In a case where a determination is performed on the
basis of a proximity state, discrimination accuracy between a large
object and a small object is improved (in a case where a
determination is performed on the basis of integration,
discrimination accuracy is further improved).
The electrostatic input device 2 according to the present
embodiment further includes the integrated value calculation unit
82 that calculates movement average values of integrated values
calculated for the respective specific regions 3A to 3C, for the
respective specific regions 3A to 3C. In a case where the palm does
not come into contact with the detection surface, detection is
difficult since variations in electrostatic capacitances
corresponding to the electrodes are very small, but there is
provided the integrated value calculation unit 82 which calculates
integrated values of variations corresponding to a plurality of
electrodes in the specific regions of the detection surface,
detected by the variation detection unit 81. Therefore, even in a
case where the palm does not come into contact with the detection
surface, and thus variations in electrostatic capacitances
corresponding to the electrodes are very small, it is possible to
determine that the palm comes close to the detection surface. Thus,
it is possible to effectively prevent an operation error caused by
the palm, and also to smoothly perform a normal operation using the
fingertip. Since the palm is larger than the finger, it is possible
to determine that the palm comes close to the detection surface by
using an integrated value in the region even if a variation in an
each electrostatic capacitance is small.
The electrostatic input device 2 according to the present
embodiment further includes the movement average value calculation
unit 83 that calculates movement average values of the integrated
values calculated for the respective specific regions 3A to 3C by
the integrated value calculation unit 82, for the respective
specific regions 3A to 3C. Therefore, it is possible to determine
that an object coming close to the detection surface is the palm by
using the movement average values of the integrated values
calculated by the integrated value calculation unit 82, and thus to
reduce the influence of noise such as a sudden increase or decrease
in an integrated value. Consequently, it is possible to more
accurately determine that the palm comes close to the detection
surface.
The control unit 85 of the electrostatic input device 2 according
to the present embodiment sets a plurality of specific regions 3A
to 3C at ends of the detection surface 3, and performs a process of
inhibiting reception of an input operation on inhibition regions of
the detection surface 3 for a predetermined period of time for the
plurality of respective set specific regions 3A to 3C. In other
words, since the specific regions are set the ends of the detection
surface 3 with which the palm easily comes into contact, and thus
it is possible to more effectively prevent an operation error
caused by the palm. Since a plurality of specific regions 3A to 3C
are set on the detection surface 3, it is possible to effectively
prevent an operation error caused by the palm at the upper end or
the left and right ends of the detection surface with which the
palm easily comes into contact.
In a case where an input operation is performed on regions other
than the inhibition regions to which the palm comes close in the
detection surface 3, the control unit 85 of the electrostatic input
device 2 according to the present embodiment cancels the inhibition
of an input operation on the detection surface 3. In a case where
an input operation is performed on regions other than the
inhibition regions, there is a high probability that the operation
may be performed with the finger, and thus it is possible to
smoothly perform a normal operation using the fingertip by
canceling the inhibition of an input operation on the inhibition
regions through the above-described process.
Other Embodiments
The present invention is not limited the above-described
embodiment. In other words, a person skilled in the art may perform
various alterations, combinations, sub-combinations, and
replacements in relation to the constituent elements of the
above-described embodiment within the technical scope of the
present invention or the equivalents thereof.
For example, in the above-described embodiment, the movement
average value calculation unit 83 calculates a movement average
value of integrated values, and the determination unit 84 compares
the calculated movement average value with a threshold value
(second threshold value), but may compare an integrated value
calculated by the integrated value calculation unit 82 with a
threshold value (first threshold value). In a case where a contact
position is moved by a predetermined amount or larger when contact
(touch) is detected in a specific region, inhibition of reception
of an input operation may be canceled.
Even in a case where contact (touch) initially detected in a
specific region is then moved to the outside of the contact
specific region, reception of an input operation may continue to be
inhibited until an initial contact position is moved by a
predetermined amount or larger. In a case where a finger operation
is determined according to other methods of discriminating the
finger from the palm, inhibition of reception of an input operation
may be canceled. At this time, inhibition of reception of an input
operation may be canceled only in a case where an operation
determined as the finger operation is performed on regions other
than inhibition regions.
In the above-described embodiment, the specific regions 3A to 3C
have been exemplified as specific regions, but a shape or a
position of a specific region are not particularly limited as long
as there is a probability that the palm may come close to the
region during an operation. An inhibition region is not required to
the same as a specific region, and, for example, an area of the
detection region is larger than that of the inhibition region, and
partial sizes thereof may be different from each other. Such
regions are preferably adjusted as appropriate depending on the
proximity detection sensitivity or the like.
It should be understood by those skilled in the art that various
modifications, combinations, sub-combinations and alterations may
occur depending on design requirements and other factors insofar as
they are within the scope of the appended claims of the equivalents
thereof.
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